All temple work for the deceased is perfumed by proxy, a living person stands in the place of the deceased and receives the ordinance on behalf of the person who is dead.  
 
This process though does not make anyone accept the ordinances performed it only gives them the opportunity to accept the ordinance perform on there behalf if they wish to do so.  
 
In the end free will is most sacred, the ordinances are performed for all because Christ commands us to ensure that all have the ability to accept the full blessings of the Gospel of Jesus Christ. If not God would cease to exist because he would then be a respecter of persons and of not said the truth when he declare he respects no man.